Lubricating composition



United States Patent Oflice 3,442,805 Patented May 6, 1969 3,442,805LUBRICATING COMPOSITION Keith L. Johnson, Matteson, Ill., assignor toSwift & Company, Chicago, 11]., a corporation of Illinois No Drawing.Filed Aug. 31, 1966, Ser. No. 576,226 Int. Cl. C10m 1/32, 3/26, /20 US.Cl. 252--34.7 4 Claims ABSTRACT OF THE DISCLOSURE A ternary lubricatingcomposition having suppressed foaming properties comprising acondensate'of a fatty acylating substance having an average of about 12to 20 carbons in the acyl group and an alkylolamine having at least oneacylatable hydrogen atom in the amino group, an alkylolamine soap of afatty acid and polypropylene glycol having a molecular weight of betweenabout 1,000 and 10,000 is disclosed. The compositions are useful in thedrawing of copper metal so that the drawing may be accomplished withsubstantially no insoluble copper soap formation.

This invention relates to an improved lubricant and coolant for use inmetal working. More particularly, the invention has to do with thepreparation of an improved lubricant having superior lubricatingproperties and a greatly reduced tendency to foam.

It is common in the drawing of copper tubing and wire to use a blend ofsoap and fat to act as a lubricant at the point of extrusion. Thislubricant is generally applied in an aqueous solution, i.e., anoil-in-water emulsion and at concentrations of 5% total solids or less.The resultant emulsion coats out on the copper wire or tubing or coppercoated wire or tubing and provides lubrication at the draw point.

Blends of soaps and fats have provided adequate lubricity, yet they arenot completely without drawbacks since there is a great tendency forthem to form insoluble copper soaps. These soaps eventually precipitateto form large quantities of flocculent material having essentially novalue in the process. In industrial practice it has been found necessaryto construct holding tanks for the soapfat emulsion in such a manner sothat they are adequately bafiled to permit the copper soaps to form anundisturbed sediment. This sediment is then manually removed from thetanks on a periodic basis.

Various attempts to improve upon the soap precipitation situation led tothe use of alkanolamine condensates and/ or salts. While some "of theseprior art compounds have overcome the problem of soap precipitation,they are not the most desirable substances due to their limitedlubricity and their great tendency to form copius quantities of foam.The great majority of operations wherein copper wire or copper tubing isdrawn involve a recirculating system where the lubricant solution isallowed to fall into the storage tank or it is circulated by pumps thatcan imbibe air into the liquid. Thus the majority of industrialinstallations are unable to take advantage of these products.

Another associated area is in the cold deformation of metals, such asthe area of cold rolling steel sheet metal. In the cold rolling of steelsheet, a lubricant is applied to the sheet material to be reduced as itenters the first stand or bite of the rolling mill. The lubricant isgenerally a quasi stable emulsion of palm oil, tallow or some otherfatty material. Generally speaking, the run-off and application ofemulsified lubricant runs into the sewer and is discarded. There areseveral disadvantages to this procedure. As part of a program toeliminate potential sources of pollution, steel mills are switching to arecirculating type system. Here again, however, the inherent foaminesspresent in most of the prior art lubricants tend to preclude their use.

Another disadvantage of the fat-type emulsion is that the lubricantemulsion actually heats up the mill. Application of heat is nownecessary to keep the internal phase of the emulsion liquid in the caseof palm oil and tallow emulsions. Thus, if the lubricants could beapplied at ambient or reduced temperatures, they would result insubstantial increases in mill efiiciency.

It is accordingly an object of this invention to provide an improvedlubricant for metal working.

It is also an object of this invention to provide a metal workinglubricant which will permit high speed rolling of steel or other metalplate.

It is a further object of this invention to provide an improvedlubricant for metal working that has a greatly reduced foaming tendency.

It is a still further object of this invention to provide a lubricantwhich will permit the drawing of copper wire, copper coated wire andtubing without the formation of water insoluble copper soaps.

An additional object of this invention is to provide a base formulationfor preparing paste type lubricants useful for the bright drawing ofcopper tubing and wire.

Additional objects, if not specifically set forth herein, will bereadily apparent to those skilled in the art from the detaileddescription of the invention which follows.

In general, the novel lubricating compositions of this inventioncomprise a ternary mixture of an alkylolamine soap of fatty acids havingan average of between about 12 and about 20 carbons in the acyl portion,a condensation product of an alkylolamine having at least one acylatablehydrogen atom in the amino group and a fatty acylating substance havingan average of between about 12 and about carbons in the fatty acidgroup, and polypropylene glycol having a molecular weight of betweenabout 1,000 and about 10,000. The condensate may be further defined ascomprising essentially fatty acid amides of the alkylolamine with anon-performance affecting amount of fatty acid monoester of thealkylolamine as well as small amounts of glycerine and free amine. Whilenot preferred, the percentage of the ester, based on the weight of thecondensate, can vary from 10 to 40% without substantially affecting thelubricating performance. However, in general, the condensate when firstformed, will have an amidezester ratio of about 7:3. In the presence ofan amine soap, the condensate is aged so that it will end up with a lowester content. This low ester content of the condensate can be definedas less than about 10%, based on the weight of the condensate.

While amounts of the ingredients of the ternary blend may vary somewhat,synergistic lubricating properties are present when the condensate ispresent in amounts of between about 44% and about 77%, the amine soappresent in amounts of about 3% to about 16% and the polypropylene glycolin amounts of about 20-40%. Slightly more specific blends include thosecompositions wherein the condensate is present in amounts of about 47%to about 71%, the soap is present in amounts of between about 6% andabout 13%, and the polypropylene glycol present in amounts of about 20%to 40%. Specific blends as to the polypropylene glycol are morepreferred in some instances and these comprise blends of about 28% to32% polypropylene glycol, about 44% to about 77% condensate and about 3%to about 16% amine soap. Most preferred compositons having synergisticlubricating characteristics yet possessing extremely low foamingproperties and being capable of forming homogenous solutions not subjectto hard water incompatability comprise those compositions containingabout 28% to 32% polypropylene glycol, about 9% to about 13% amine soapand about 57% to 61% condensate. The above percentages are all weightpercents.

More in detail as to the description of the various components, thepolypropylene glycol may be formed by the polymerization of propyleneoxide with propylene glycol. The terminal oxyalkylene group may be abutylene oxide or an ethylene oxide, as well as propylene oxide. Ofspecial importance are the polypropylene glycols having molecularweights varying between about 1,000 and about 10,000. The preferredresults are produced using polypropylene glycol having a molecularweight of approximately 2,000.

In preparing the amine soap and condensate, it is preferred to makemixtures of the condensate and amine soap and combine them withcondensate containing some free amine. That is, in producing the amide,equal parts by weight of a fatty acylating agent and alkylolamine may beheated at temperatures varying between about 140 C. and 200 C. for /2 to6 hours. The resulting mixture may then be cooled and to three parts ofthe said mixture one part of a fatty acid averaging between about 12 and20 carbon atoms is added. That free fatty acid forms the soap with theunreacted alkylolamine from the initial condensation, That resultingblend consists of about 50 parts condensate, 35 parts amine soap, and atotal of 15 parts free amine and glycerin. Perhaps it should be statedat this point that the free amine, while desirable, is not essential andthat generally speaking the free amine and glycerin have substantiallyno effect on the superior lubricating properties of the finalcomposition. Approximately 30% of the resulting mixture is then blendedwith 40% of a product formed by the reaction of about 3 parts of fattyacid with one part of alkylolamine at temperatures of around 300 F.under vacuum to form a mixture of about 90 parts condensate and about 10parts free amine. The entire mass can then be blend with about 30 partsof polypropylene glycol to arrive at a final composition having about33% polypropylene glycol, about 57% condensate and about 11% amine soap.

A specific example of preparing an amine soap and condensate is asfollows:

The amide of coconut oil is produced by heating equal parts of coconutoil and diethanolamine to a temperature of about 150 C. for a period of3-4 hours. The resulting mixture is then cooled and three parts of saidmixture are blended with one part of oleic acid. The oleic acid formsthe soap with the free or unreacted diethanolamines from the initialcondensation. The resultant blend consists of glycerine, free orunreacted diethanolamine, diethanolamide of coconut fatty acids, andrelated by-products in the diethanolamine soap of oleic acid.

A solution containing a predominant amount of condensate is prepared byreacting 73 parts of oleic acid with 27 parts of diethanolamine. The twoingredients are caused to react at a temperature of approximately 300 F.under vacuum of about 27-29 inches of mercury. Generally about 30% byweight of the first-described product is combined with 40% by weight ofthe condensate product and with 30% of a polypropylene glycol. Such acomposition, even though containing small amounts of glycerine and freeamine, will exhibit excellent lubricating properties. The amine, whilenot essential, is preferred in some instances where bright drawing ofcopper metals is contemplated.

In the above-described reactions, diethanolalrnine or diisopropanolaminewill generally be used. However, monoalkanolamines such asmonoethanolamine or monoisopropanolamine may be used either alone or inmixtures with diethanolamine or diisopropanolamine to form thecondensate. Mixtures containing mono-, di-, or trialkanolamines may bealso used with the trialkanolamine forming the soap component. Theacylating substance is preferably a monocarboxylic acid or derivativethereof having 4 an average of 12 to carbons in the acyl portion. Byacylating substance is meant any substance which is capable of theformation or introduction of an acyl radical in or into the alkylolamineand includes carboxylic acids, carboxylic acid halides, carboxylic acidesters and anhydrides. In regard to the esters, the term is meant tocover both esters of monohydric alcohols and esters of polyhydricalcohols such as the glycerol esters,

The ternary ingredients of the compositions of this invention weretested singly and in combination on the Baroid mud tester. This machinewas designed to evaluate extreme pressure, lubricant additives todrilling mud and measures inch pounds of torque between zero and 600pounds. Modification had to be made in the torque wrench portion of theapparatus in order to measure the readings at the optimum synergisticareas. The mud tester is essentially a takeoff on the Timken weartesting machine using a smaller cup and the same size block. Theprinciple is that the rotating cup or ring is brought into contact withthe block of metal while the entire system is immersed in the lubricantsolution being tested. Torque is applied to the torque wrench and thevalue at which the amperage required by the motor takes a sharp jump isnoted. This sharp jump indicates lubricant failure at the interfaceresulting in an increased load on the motor.

The individual values for polypropylene glycol having a molecular weightof about 2,000 averaged inch pounds of torque at seizure. For thecondensate, i.e., the amide with a low ester content, the value was 380inch pounds of torque while with the amine soap, the value was about 320inch pounds of torque at seizure. Accordingly, it can be seen that onewould normally expect the value at seizure to be somewhat less than 380inch pounds of torque when the three ingredients are combined in anygiven ratio. While it is true that torque values of less than 380 inchpounds are produced at various ratios of ingredients, it wasunexpectably found that at certain levels, the ternary mixture producedclearly synergistic results. When using a ternary blend of ingredientsin the ratios set forth in the earlier part of this specification,torque values well above 450 inch pounds were obtained. The lubricatingvalue at the point described as the optimum blend was in excess of 635inch pounds of torque at seizure. Such values were produced using acomposition containing about 30% polypropylene glycol, about 60%condensate and about 10% amine soap..

The following examples are presented to illustrate the invention. Itwill be understood that these examples are illustrative only and shouldnot be taken in any manner as limiting the invention as defined by theappended claims.

EXAMPLE I In the charts set forth in this example the amine soap isdiethanolamine oleate having the structure:

(I) H CHzCHzOH CuHuJl-O-l-N CHzCHaOH The condensation product isessentially the diethanolamide of coconut oil and oleic acid with a lowester content. The amide may be represented by the formula:

CHzCHzOH CHICHIOH CHART NO. 1

Condensation Polypropylene Product Glycol Torque 20 440 in lb. 54.4 20308m lb. 57.6 20 main lb. 60.8 20 308111 lb. 64.0 20 403 in lb. 67.2 20532111 lb. 70.4 20 515 in lb. 73.0 20 362 in lb. 76.8 20 434 in lb.

CHART NO. 2

Condensation Polypropylene Product Glycol Torque Amine Soap:

0 30 370 in. lb. 47.6 30 293 in. lb. 50.8 30 243111.1b. 54.0 30 438 inlb. 57.2 30 490 in In. 60.4 30 635 in lb. 63.6 30 407 in lb. 66.8 30 437in lb. 70.0 30 217 in lb.

CHART N0. 3

Condensation Polypropylene Product Glycol Torque 0 40 370m. lb. 40.8 40340 in. lb. 44.0 40 479 in. lb. 47.2 40 548 in. lb. 50.4 40 461 in. lb.53.6 40 520ln.lb. 56.8 40 468 in. lb. 60.0 40 294 in. lb.

CHART NO. 4

Condensation Polypropylene Product; Glycol Torque 0 100 150 in. lb. 6040 293 in. lb. 70 30 213 in. lb. 100 0 380 in. lb.

CHART N O. 5

Polypropylene Amine Soap Glycol Torque 100 0 320 in. lb. 80 440in.1b. 70370m. lb. 60 40 370 in. lb. 0 100 150 in. lb.

CHART N O. 6

Condensation Amine Soap Product Torque 100 0 320 in. lb. 65 235ln.1b. 0100 380 in. 1b.

EXAMPLE II Various experimental runs were made using the lubricant ofthis invention dispersed in water of concentrations ranging from aboutpercent to about 10%. Copper tubing, copper wire, and copper coatedsteel wires were drawn through various dies lubricated with thecompositions containing about 11% amine soap, 59% condensate and 30%polypropylene glycol. The ternary ingredients are those defined inExample I. Using this system, a very adequate die life was observed.Perhaps one of the outstanding properties of the ternary lubricatingcomposition was the fact that essentially no flocculent copper soapswere formed during the drawing process. Accordingly, there was noproblem of sludge formation.

In addition, the ternary lubricants can be the basis for formulating apaste-type lubricant used in the bright drawing of copper wire as shownby the following example.

EXAMPLE III The ternary lubricant in an amount of 45%, by weight, wascombined with 25%, by weight of water and about 30% diatomaceous earth.These materials were blended together in a Mixmueller crutcher designedto handle high viscosity pastes. This paste had a stable viscosity overa relatively wide temperature range, i.e., to F. Copper wire drawnthrough the paste had a very bright finish.

EXAMPLE IV The improved lubricants of this invention may also be usedfor the working of ferrous materials such as steel. Using the optimumblends set forth in Example I as the lubricating composition in thecold-rolling of steel, it was found possible to roll at a speed of 3,500feet per minute to reduce the thickness of the sheet from .05 inch to.017 inch in a 1 stand mill. The steel was adequately lubricated with nostaining of the worked surfaces. One attractive feature of this systemwas that the lubricant was applied at ambient temperatures. This is incontrast to the normally used palm oil or tallow emulsions which must beheated. Using the instant lubricant at ambient temperatures naturallydecreases the temperature of the mill.

While specific examples have been set forth above, it should be noted atthis time that the improved lubricating compositions of this inventionare adaptable for lubricating metals during various processingoperations such as cutting, drilling, tapping, milling, drawing and thelike. The lubricating compositions of this invention may be used at fullstrength, however, they are generally dispersed in water in amounts of Ato 10%., preferably 24%. In some instances oil-in-water emulsions may beformed. However, for purposes of this specification, the term dispersingwill include all types of colloidal systems including emulsions.

It is apparent that many modifications and variations of the inventionmay be made without departing from the spirit and scope thereof and,accordingly, only such limitations should be imposed as are indicated inthe appended claims.

I claim:

1. A ternary lubricating composition having suppressed foamingproperties comprising a condensate, in an amount of between about 44%and about 77%, which contains predominantly an amide prepared by thereaction of a fatty acylating substance having an average of about 12 to20 carbon in the acyl group and an alkylolamine having at least oneacylatable hydrogen atom in the amino group; an alkylolamine soap of afatty acid in an amount of between about 9% and about 13%; andpolypropylene glycol having a molecular weight of between about 1,000and about 10,000 in an amount of between about 20% and about 40%.

2. The composition of claim 1 wherein the condensate is present in anamount of between about 57%, to about 61%, the amine soap is present inan amount of between about 9% and about 13% and the polypropylene glycolis present in an amount of between about 28% to about 32%.

3. The composition of claim 1 wherein the condensate comprises an amideof a member selected from the group consisting of diethanolamine anddiisopropanolamine and the acylating agent is selected from the groupconsisting of coconut oil and oleic acid or mixtures thereof.

4. The composition of claim 1 wherein the amine soap is selected fromthe group consisting of monoethanolamine oleate, monopropanolamineoleate, diethanolamineoleate, diisopropanolamine oleate, triethanolamineoleate, triisopropanolamine oleate and mixtures thereof.

References Cited UNITED STATES PATENTS 2,079,803 5/1937 Holtzclaw et a1.252-495 XR 2,624,708 1/1953 Langer et a1. 25249.3 XR 2,668,146 1/1954Cafcas et a1 25233.4 3,177,144 4/1965 Reamer et a1. 252-49.3 XR 103,233,442 2/1966 Zvanut 25249.3 XR 3,244,638 4/1966 Foley et a1. 25249.5XR 3,311,557 3/1967 Schiermeier 25249.3 XR

DANIEL E. WYMAN, Primary Examiner.

W. H. CANNON, Assistant Examiner.

US. Cl. X.R.

